Transfer Section Switching Voltage and Current Control for Image Quality

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image forming apparatuses face challenges in maintaining a consistent transfer electric-field across different types of recording media, leading to variations in transfer current paths, which can result in insufficient transfer current and poor image quality, especially when dealing with papers of varying resistance values.

Innovation Solution

An image forming apparatus is designed with a transfer section that includes a transfer member, an opposite member, and a contact section to apply a transfer electric-field, along with resistance detection sections to compare system resistances and switch between constant voltage control and constant current control based on the type of recording medium, ensuring the transfer electric-field remains within an appropriate range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If constant voltage control is used for the transfer electric-field, then the control is simple and stable, but the transfer current varies significantly with different recording media resistance values, leading to insufficient transfer current for high resistance papers

Engineering Contradiction:

Improvetransfer operation reliabilityVSAvoidadaptability to different recording media

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic switching between constant voltage control and constant current control modes based on the resistance value of the recording medium. The control section detects the resistance value and automatically selects the appropriate control mode, making the transfer section adaptable to different recording media while maintaining reliable transfer operations

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter from fixed constant voltage to variable control (switching between constant voltage and constant current modes) based on the recording medium's resistance value. This parameter change enables the system to handle both low resistance and high resistance papers effectively

Inventive Principle:

Principle #35Parameter changes

2Reliability

If constant current control is used for the transfer electric-field, then the transfer current is maintained consistently, but the transfer electric-field becomes excessive for low resistance papers, causing image quality degradation

Engineering Contradiction:

Improvetransfer current consistencyVSAvoidexcessive transfer electric-field effect

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the control parameter from fixed constant current to variable control (switching between constant current and constant voltage modes) based on the recording medium's resistance value. This prevents excessive transfer electric-field effects on low resistance papers while maintaining consistent transfer current for high resistance papers

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If a single control mode is used for all recording media, then the control system is simple, but the transfer electric-field cannot be maintained within the necessary range for varying resistance values

Engineering Contradiction:

Improvecontrol system complexityVSAvoidtransfer electric-field stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration effectively maintains the transfer electric-field within a necessary range, ensuring proper transfer operations even with varying recording media, preventing image quality issues and transfer failures, and allowing for efficient handling of both low and high resistance papers.

Implementation Method 1

a transfer section that applies a transfer electric-field to a transfer region and electrostatically transfers the image held by the image holding section onto a recording medium transported to the transfer region

Methodology Applied

Scientific EffectElectrostatic transfer: Electrostatics

Data Source

PatentUS10955773B2Image forming apparatus having transfer section switching between a constant voltage control and constant current control

Publication Date: 2021.03.23 FUJIFILM BUSINESS INNOVATION CORP

AI summary

An image forming apparatus includes: an image holding section; a transfer section that includes a transfer member, applies a transfer electric-field to a transfer region between the image holding section and the transfer member, and electrostatically transfers an image held by the image holding section onto a recording medium; a contact section that acts as an electrode to ground while being in contact with the recording medium when the recording medium passes through the transfer region; a first resistance detection section; a second resistance detection section; a comparison section that compares a first system resistance detected by the first resistance detection section with a second system resistance detected by the second resistance detection section; and a switching section that switches between constant voltage control and constant current control for the transfer electric-field produced by the transfer section depending on a result of comparison by the comparison section.